Determining the pore structure characteristics and influencing factors of continental shale reservoir in the oil generation stage is of great significance for evaluating the shale oil reservoir space and analyzing shale oil enrichment mechanism. In this paper, shale from the first member of the Upper Cretaceous Qingshankou Formation (K₂qn₁) in the Songliao Basin was selected. X-ray diffraction (XRD), Rock-Eval pyrolysis, total organic carbon content (TOC), scanning electron microscopy (SEM), nitrogen gas adsorption (N₂GA), and high-pressure mercury injection (HPMI) were used to clarify the composition characteristics of inorganic minerals and organic matter and determine the influencing factors of pore development in the K₂qn₁ shale. The results show that intergranular pores related to clay minerals and quartz, intragranular dissolution pores related to feldspar, and other mineral intragranular pores are developed. The organic matter pore is less developed, mainly composed of intragranular pores and crack pores of organic matter. Mesopores related to clay minerals are widely developed, rigid quartz particles can protect and support mesopores and macropores, and carbonate cementation can inhibit pore development. Although the TOC contents of shale are commonly less than 2.5%, it has a good positive correlation with porosity; TOC is greater than 2.5%, and the increase of residual oil fills part of the pores, leading to a decrease in porosity with the increase of TOC. Three types (types I, II, and III) of the reservoir space were classified by the combined pore size distribution diagram of N₂GA and HPMI. By comparing the characteristics of pore structure parameters, it is found that Type I reservoir space is favorable for shale oil enrichment. It provides scientific guidance for shale oil exploration in the Songliao Basin.

中文翻译：

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储层组成对陆相页岩孔隙结构的影响——以松辽盆地北部三照凹陷青山口组为例

确定陆相页岩生油期孔隙结构特征及影响因素，对评价页岩油储集空间、分析页岩油富集机理具有重要意义。本文选取松辽盆地上白垩统青山口组第一段(K ₂ qn ₁ )页岩。X 射线衍射 (XRD)、Rock-Eval 热解、总有机碳含量 (TOC)、扫描电子显微镜 (SEM)、氮气吸附 (N ₂ GA) 和高压汞注射 (HPMI) 用于澄清K ₂ qn无机矿物和有机质组成特征及孔隙发育影响因素的确定₁页岩。结果表明，发育与粘土矿物和石英有关的粒间孔、与长石有关的粒内溶蚀孔和其他矿物的粒内孔。有机质孔隙较不发育，主要由有机质粒内孔隙和裂隙孔隙组成。与粘土矿物相关的介孔广泛发育，刚性石英颗粒可以保护和支撑介孔和大孔，碳酸盐胶结作用可以抑制孔隙发育。页岩的TOC含量虽然一般小于2.5%，但与孔隙度呈良好的正相关；TOC大于2.5%，残余油的增加填充了部分孔隙，导致孔隙率随着TOC的增加而降低。三种类型（I、II、₂遗传算法和 HPMI。通过对比孔隙结构参数特征，发现Ⅰ类储集空间有利于页岩油富集。为松辽盆地页岩油勘探提供科学指导。